Hitachi, Ltd.

Hitachi Tobu Semiconductor

Hitachi Iruma Electronic Company Ltd.

Hitachi Iruma Electronic Corp., Ltd.

Kunio Aiki

Tugio Nemoto

Satoru Ishii

Naoki Chinone

Michiharu Nakamura

Atsushi Sasayama

Haruo Kugimiya

Takashi Kajimura

Jun-ichi Umeda

Makoto Haneda

Yasutoshi Kashiwada

Ryoichi Ito

Tutomu Kawasaki

Takao Kuroda

Shigeo Yamashita

Toshiaki Tanaka

Yoshito Tsunoda

Kimio Tatsuno

Satoshi Nakamura

Kazuhisa Uomi

Masahiro Ojima

Yuichi Ono

Tetsuo Kumazawa

Toshihiro Kawano

Makoto Shimaoka

Shin'ichi Nakatsuka

Toshimitsu Miyauchi

Yutaka Takeda

Junichi Umeda

Atsutoshi Doi

Yasutoshi Yagiu

Tsunetoshi Kawabata

Akemi Yamanaka

Hitachi, Ltd

Jun-Ichi Umeda

A collimated-beam generating device using a semiconductor laser includes a two-lens system in which light converged by a first lens is converted into a collimated beam by a second lens, whereby a distance between the semiconductor laser and the first lens is made large, assembly of the device is made easy, and a collimated beam having a small beam diameter can be produced.

Semiconductor light emitting device and apparatus using the same

In a photoelectric device, particularly, a photoelectric device for optical communication, an optical fiber is fixed at two fixing points so that the extremity of the optical fiber is disposed opposite to the light emitting surface of a laser diode chip and the optical fiber extends in a nonlinear shape, for example, in a moderate curve, between the two fixing points. Even though holding members fixedly holding the optical fiber at the two fixing points and a base member supporting the holding members are formed of a metal or metals having a coefficient of thermal expansion far greater than that of the optical fiber, and even if the distance between the two fixing points is varied due to the thermal expansion or contraction of the holding members and the base member, the optical fiber is obliged only to change the shape of extension. Therefore, the optical fiber and the solder fixing the optical fiber to the holding members at the two fixing points are not subjected to repeated stress, and hence the fatigue of the optical fiber and the solder is avoided. Accordingly, the photoelectric device is able to continue stable optical communication regardless of temperature variation.

Method of mounting a light emitting chip and an optical fiber on a

In a photoelectric device, particularly, a photoelectric device for optical communication, an optical fiber is fixed at two fixing points so that the extremity of the optical fiber is disposed opposite to the light emitting surface of a laser diode chip and the optical fiber extends in a nonlinear shape, for example, in a moderate curve, between the two fixing points. Even though holding members fixedly holding the optical fiber at the two fixing points and a base member supporting the holding members are formed of a metal or metals having a coefficient of thermal expansion far greater than that of the optical fiber, and even if the distance between the two fixing points is varied due to the thermal expansion or contraction of the holding members and the base member, the optical fiber is obliged only to change the shape of extension. Therefore, the optical fiber and the solder fixing the optical fiber to the holding members at the two fixing points are not subjected to repeated stress, and hence the fatigue of the optical fiber and the solder is avoided. Accordingly, the photoelectric device is able to continue stable optical communication regardless of temperature variation. Terminals are formed by leads having an inductance reducing thick portion that are connected to the photoelectric device inside a box-shaped housing. A thinner lead conforming to the prevailing standard connector is connected to the thick lead using ultrasonic bonding at a position outside of the housing.

Photoelectric device with leads

A light emitting device including a light emergence device, an optical fiber for receiving light emerging from the light emergence device, and an optical fiber supporting member having a groove or hole for accommodating and fixing the optical fiber. The support member is adapted to be deformed when subjected to an external force so as to enable an alignment of the optical axes of the light emergence device and the optical fiber.

Method of assembling a light emitting device with an optical fiber

Light emitting device with an optical fiber and a deformable support

Photoelectric device with optical fiber and laser emitting chip

In the photo electro device, a laser diode chip is set fixedly through a submount to a heatsink in a package. In assembling, first a ball lens is anchored to a holder of a lens support frame by clinching claws of the holder. Subsequently the surfaces of the ball lens on the obverse and reverse sides of the lens support frame are coated with nonreflective films. Then the position of the lens support frame is adjusted relatively to the laser diode chip so that the respective optical axes are aligned with each other. And after an arm is welded fixedly to the heatsink, a frame member is severed or removed to complete the work for setting the ball lens.

Photo electro device, method for manufacture of same, and lens support

A semiconductor laser device having a stripe-shaped active region defined between a pair of end surfaces, at least one of the end surfaces having a curved cross-section in a plane parallel to the active region with a radius of curvature from 10 to 300 .mu.m, the stripe of the active region having such a width that a single transverse mode and a multi-longitudinal mode are allowed. The laser beam emitted from this laser can have little astigmatism and small spot size.

Semiconductor laser device having little astigmatism

Disclosed herein is a semiconductor laser device including at least an optical confinement region having at least first, second and third semiconductor layers disposed on a semiconductor substrate, wherein the first and third semiconductor layers have refractive indices greater than the refractive index of the second semiconductor layer but have forebidden band gap smaller than that of the second semiconductor layer and the conductivity types of the first and third semiconductor layers are opposite to each other; the second semiconductor layer has a smooth change of its thickness in two directions parallel to a junction surface of the optical confinement region; and a difference exists in the refractive indices of the first and third semiconductor layers.

Buried heterojunction laser

A semiconductor laser device including at least a laminated region of first, second, third and fourth semiconductor layers on a predetermined semiconductor substrate, wherein the third semiconductor layer has a refractive index smaller than that of the second semiconductor layer; the first and fourth semiconductor layers have a refractive index smaller than that of the second and third semiconductor layers and have a conductivity type opposite that of the second and third semiconductor layers; the forbidden band gap of the first and third semiconductor layers is greater than that of the second semiconductor layer; and at least the second and third semiconductor layers are bent so that the laser light generated inside the second semiconductor layer in the proximity of the laser light-emitting facets generates optical coupling in the third semiconductor layer and is emitted from the crystal facets of the third semiconductor layer. The device of the present invention is effective for increasing the output of semiconductor laser devices.

Semiconductor laser device

An optical pickup wherein a semiconductor laser device for projecting a laser beam onto an optical disc is driven by a D.C. current and a high-frequency current superposed thereon, and the laser device oscillates in a multiple longitudinal mode.

Optical pickup

In a semiconductor laser device having at least a first semiconductor layer, second and third semiconductor layers which are formed in a manner to sandwich the first semiconductor layer and which have a wider band gap and a lower refractive index than those of the first semiconductor layer, an optical resonator and carrier injection means; a semiconductor laser device characterized in that at least said first semiconductor layer has an angle of inclination (.theta.) relative to an axis which is perpendicular to optically flat faces constituting said optical resonator. The inclination angle .theta. (rad) should most preferably lie in a range of: ##EQU1## where .theta..sub.z denotes a reflection angle, .theta..sub.c a critical angle, W 1/2 of a thickness of a waveguide, and l a cavity length. The laser device is effective for preventing laser facets from breaking down, and can produce high power.

A semiconductor laser device of this invention has a built-in passive guiding mechanism along the junction plane by growing planar double hetero (DH) layers on a grooved or projected substrate. It operates stably in the lowest transverse mode and provides light-output versus current characteristics free of either kinks or any anomalies.

A semiconductor laser device is formed of a semiconductor material assembly including a first semiconductor layer having an active region formed directly by crystal growth on a substrate for the crystal growth having on the surface thereof a second semiconductor layer. A third semiconductor layer is also formed on the first layer. The refractive index of each of the second semiconductor material region and the third semiconductor layer is smaller than that of the first semiconductor layer while the band gap of each of the second semiconductor material region and the third semiconductor layer is broader than that of the first semiconductor layer. In order to provide mode stabilization even at long wavelength, the thickness of the active region formed at the interface between said first semiconductor layer and said substrate for crystal growth is made larger than the thickness of the other portions in the first semiconductor layer so that the effective refractive index to laser beams is changed stepwise in a direction perpendicular to the direction of the laser beams.

Growing community of inventors

Takasaki, Japan

Kunio Aiki